Uploading file using multer and then use it

Question

I'm uploading my file using multer, and then I'm trying to read the JSON file and do some operations for it. Apparently, when I take the name of the file and pass it to my function I'm getting the error following error:

The code inside my app.js

//UPLOAD FILE READER
const storage = multer.diskStorage({
  destination: (req, file, cb) => {
    cb(null, 'points')
  },
  filename: (req, file, cb) => {
    const { originalname } = file;
    cb(null, originalname)
  }
})

const upload  = multer ({ storage })

//Function to get the name of the file for future use
var splitTest = function (str) {
  return str.split('\\').pop().split('/').pop();
}


app.post("/uploadFile",upload.single('fileupload'),(req, res, next) => {
    // Read File Before Uploading
    const absolutePath = path.join(__dirname, req.file.path);
    const jsonString = fs.readFileSync(absolutePath, "utf-8");
    const jsonObject = JSON.parse(jsonString);
    nameFile = splitTest(absolutePath)

    //JSON SCHEMA VALIDATOR
    var innerSchema = schemas.jsonSchema;
    var innerArraySchema = {
      "type": "array",
      "items" : innerSchema
      }
    const ajv = new Ajv()
    const valid = ajv.validate(innerArraySchema, jsonObject)
    if (!valid) {
      fs.unlinkSync(req.file.path)
      res.redirect('admin')
    }
    else {
    console.log(nameFile)
    rFile(nameFile)
    res.redirect('admin')
    }
})

Also the function I call inside my app.js.

//Load JSON DATA to MySQL
rFile("starting_pois.json") --> For testing its working perfectly
function rFile(fileName) {
  fs.readFile(`../points/${fileName}`, 'utf-8', (err, jsonString) => {
  // Do stuff....